murmur

1[transitive,intransitive]murmur (something)+ speechmurmur that…to say something in a soft, quiet voice that is difficult to hear or understandShe murmured her agreement.He murmured something in his sleep.She was murmuring in his ear.

2[intransitive]to make a quiet continuous soundThe wind murmured in the trees.

3[intransitive]murmur (against somebody/something)(literary)to complain about someone or something, but not openlyThe people murmured against the new regime.